Parasit. Hung. 6. 1973.

Nematodes Associated with Coleoptera Species in Egypt. II .

Mohamed A L I — Ahmed W A H A B - Ahmed H . E L - K I F E L

Department of Economic Entomology, Agricultural College, Al-Azhar University, Cairo

"Nematodes Associated w i t h Coleoptera Species i n Egypt. I I . " - A l i , M., Wahab, A., E l - K i f e l , A.H.- P a r a s i t . Hung. 6 . 169-188 . 1973-

A number of 797 b e e t l e s r e p r e s e n t i n g the f a m i l i e s Carabidae, Scarabaeidae, Tenebrionidae and H i s t e r i d a e were examined ex­t e r n a l l y and i n t e r n a l l y f o r nematode p a r a s i t e s . Nematode larvae i s o l a t e d were reared on c u l t u r e media t o the a d u l t stage f o r i d e n t i f i c a t i o n . 268 b e e t l e s (33-6 rS) were found i n f e s t e d by nematodes. Only e x t e r n a l i n f e s t a t i o n was noted. Seven nematode species r e p r e s e n t i n g f o u r f a m i l i e s were i d e n ­t i f i e d , f u l l y described and also t h e i r p o s s i b l e adverse e f ­f e c t t o the host was discussed.

Introduction

Nematodes invading i n s e c t s as p a r a s i t e s were and are o f great importance t o b i o l o g i s t s , not only from the b i o l o g i c a l c o n t r o l p o i n t of view, but also f o r p h y s i o l o g i c a l s t u d i e s .

The r e l a t i o n between i n s e c t s and nematodes was i n t e r m i t t e n t l y s t u d i e d and discussed by v a r i o u s i n v e s t i g a t o r s . Studies i n t h i s respect were c a r r i e d out t o r e v e a l v a r i o u s phenomena concerning symbiosis, p a r a s i t i s m , and the e x t e r n a l or i n t e r n a l e f f e c t s of nematodes on t h e i r h o s t s . Research workers i n these f i e l d s also aimed to f i n d a p p l i c a t i o n i n b i o l o g i c a l c o n t r o l .

I n Egypt, the nematode and i n s e c t r e l a t i o n s h i p was not e x t e n s i ­v e l y discussed so far.The a s s o c i a t i o n of nematodes w i t h i n s e c t s was i n v e s t i g a t e d by JANET ( 1 8 9 3 ) , FUCHS ( 1915 ) , GLASER (1932) ,

PILIPJEV (1934), THORHE (1935), MOORE (1955) and WELCH (1958). JAHET (1893) was the f i r s t who stu d i e d the a s s o c i a t i o n of nema­todes w i t h the b e e t l e Ocnera h i s p i d a Porsk ., (Coleoptera, Tene-b r i o n i d a e ) . PUCHS (1915) c a l l e d a t t e n t i o n t o the f a c t t h a t the moist f r a s s of mines produced by Ips typographus L. and Hylo-bius a b i e t i s L. was i n h a b i t e d by la r g e number o f s p e c i f i c nemic fauna, the members of which were i n more or l e s s close symbio­t i c r e l a t i o n s h i p w i t h the b e e t l e s . He also observed t h a t cer­t a i n nemas were c a r r i e d out by bee t l e s e i t h e r under the wings or i n some other ways.

The recent works of nematode a s s o c i a t i o n w i t h i n s e c t s through the p e r i o d 1960-1968 were discussed by MASSEY ( i 9 6 0 ) , WALLACE (1961), WAHAB (1962), GOODEY ( I 9 6 3 ) , WELCH (1962), ROSTOM ( 1 9 6 6 ) and ALI et a l . (1972). The s o i l nematode genera Diplo-g a s t e r , R h a b d i t i s , Pelodera, Mesorhabditis and Panagrolaimus, i n c l u d i n g species of known a s s o c i a t i o n w i t h i n s e c t s , were r e ­ported i n OTEIPA's ( 1 9 6 4 ) work.

Material and Methods

The v a r i o u s i n s e c t species were c o l l e c t e d i n d i f f e r e n t areas (the farm of the A g r i c u l t u r e College a t Mosttord, Abu-Rawash and Giza) and on d i f f e r e n t dates d u r i n g the p e r i o d extending from 1965 t i l l the end of 1967. The h a b i t a t of the i n s e c t s va­r i e d g r e a t l y . C e r t a i n i n s e c t s l i v e i n the s o i l sub surface or dwell i n heaps of organic manure, e i t h e r as a d u l t s or immature stages.

Methods have already been described by ALI et a l . (1972).

A b b r e v i a t i o n s of nematode d e s c r i p t i o n : AN = Anus: CR = corpus: CA = caudal alae ( b u r s a ) : EBE = end bulb of esophagus: CP = caudal p a p i l l a : GUB - gubernaculum: INT = i n t e s t i n e : L I = l i p : MPS = median pseudobulb: NR = nerve r i n g : CV = ovary: PR - prostome: R = rectum: SPI = sp i c u l e s : TE = telostome: UT = ut e r u s : VEB = valve o f esophagus end-bulb: VU = v u l v a

Results

I n the f o l l o w i n g i n s e c t i n f e c t i o n w i t h nematodes i s discussed and nematode species i s o l a t e d from the i n f e s t e d b e e t l e s are de­s c r i b e d .

1. Anisodactylus ( H e x a t r i c h u s ) v i r e n s Dej .

197 b e e t l e s of Anisodactylus ( H e x a t r i c h u s ) v i r e n s D e j . (Coleop­t e r a : Carabaeidae) were examined e x t e r n a l l y and i n t e r n a l l y , of which 15 beetles (7.61 %) were found t o be i n f e s t e d by nemato­des .

Pi g . 1 : Panagrolaimus subelongatus (Cobb, 1914) Thorne, 1937 A - Female f r o n t end w i t h esophagus B - Female v u l v a l r e ­g i o n w i t h eggs, l a t e r a l view. C - Male t a i l , l a t e r a l view. D -Female t a i l , l a t e r a l view. ]_7l

The nematode l a r v a e were found t o predominate on the mouth p a r t s , on the abdominal segments, e s p e c i a l l y a t the coxal a t t a ­chements and underneath the a p i c a l p a r t s of the e l y t r a . 38 ne­matode larvae were e x t r a c t e d from the 15 i n f e s t e d b e e t l e s . The r e a r i n g of these l a r v a e on v a r i o u s a r t i f i c i a l media showed t h a t meat e x t r a c t and potatoe scrappings media were more s u i t a b l e than others f o r nematode growth.

A d u l t nematode males and females appeared i n the c u l t u r e s i n about one week.Microscopic examinations and measurements proved t h a t the nematodes e x t r a c t e d belong t o two species, v i z : Pana- grolaimus subelongatus (Cobb, 1914) Thorne, 1937, and Nematoda sp? Of 197 b e e t l e s , 10 (5-08 % ) specimens were found to be i n ­f e s t e d by Panagrolaimus subelongatus, and 5 (2 .53 % ) b e e t l e s by Nematoda 3p ?. Their morphological d e s c r i p t i o n i s as f o l l o w s .

1-1. Panagrolaimus subelongatus (Cobb, 1914) , Thorne 1937 ( P i g . 1 )

Females (n= 10): 1 = 1.023-1.188 mm̂ a = 24.4-27.6; b= 6.0-6.4; c = 14.4-16.6; V = 57-58 %. Males (n = 1 0 ) ; L = 0 .792-0 .858 mm; a = 25-27 .3 ; b = 4.4-4.7: c = 15.8-16.8.

L a t e r a l l i p s u s u a l l y smaller than submedian one .Cheilorhabdions l i g h t l y s c l e r o t i z e d . Prorhabdions massive, w i t h basal expan­s i o n s . Hight of l i p s v a r y i n g considerably i n populations from w i d e l y separated areas. Corpus of esophagus c y l i n d r o i d t o s l i g h t l y f u s i f o r m ( F i g . 1A). Phasmids near beginning of t e r m i ­n a l f o u r t h of t a i l .

Female a d u l t w i t h two w e l l developed gonads, each c o n s i s t i n g of an ovary, o v i d u c t and u t e r u s . Ovaries r e f l e x e d back ( F i g . I B ) . Female t a i l 71-76 ja, w i t h conoid t o acute terminus ( F i g * I D ) .

Male t a i l 50-51 M* conoid w i t h , 1 or 2 p a i r s of conspicuous

172

P i g . 2 : Pelodera s e r r a t a (Körner i n Osche, 1952) Dougherty, 1955

A - Female f r o n t end w i t h esophagus, l a t e r a l view. B - Female stoma. C - Female vulva r e g i o n w i t h few eggs, l a t e r a l view. D -Female t a i l , l a t e r a l view. E - Male t a i l , l a t e r a l view. F - Ma­l e t a i l w i t h s p i c u l e s and gubernaculum, l a t e r a l view. G - Male t a i l , v e n t r a l view. H - Male s p i c u l e s and gubernaculum. I -Mating appearance of P. s e r r a t a . yi'

dor so-sub median p a p i l l a e (Pig • l C ) . Spicules 21-22 j t i , a cute, gubernaculum about 16-18 ,u i n l e n g t h . H a b i t a t : Anisodactylus ( H e x a t r i c h u s ) v i r e n s Dej . L o c a l i t y : Abu-Rawash, Cairo, UAR.

2. O n i t i c e l l u s ( E u o n i t i c e l l u s ) p a l l e n s O l i v .

Several specimens of O n i t i c e l l u s ( E u o n i t i c e l l u s ) p allens O l i v . (Coleoptera: Scarabaeidae) were c o l l e c t e d from manure heaps at Mosttord and also from cow-dung at Abu-Rawash on d i f f e r e n t oc­casions during a p e r i o d of 19 months.

E x t e r n a l and i n t e r n a l examinations showed t h a t of 202 b e e t l e s only 121 specimens (59.9 % ) were i n f e s t e d w i t h nematodes

The nemas appeared considerably crowded under the e l y t r a and c e r v i c a l membranes. The w r i t e r was able t o e x t r a c t 3584 l a r v a l p a r a s i t e s from the i n f e s t e d b e e t l e s at a mean o f 29.6 i n d i v i ­duals per b e e t l e . The nematode l a r v a e were reared on s e v e r a l a r t i f i c a l media. A f t e r a p e r i o d of one week, the m a j o r i t y of the incubated l a r v a e reached t h e i r a d u l t stages.

Microscopic examinations and measurements of males and females showed t h a t they represent two nematode species: Pelodera ser­ r a t a (Körner i n Osche, 1952) Dougherty, 1955, and Pelodera t e ­ res (Schneider, 1366) Dougherty, 1955, whose d e s c r i p t i o n s f o l l ­ows. ( P i g . 21 shows the mating of the former species.)

2-1. Pelodera (Coarctadera) s e r r a t a (Körner i n Osche, 1952) Dougherty, 1955 ( F i g . 2 )

Females (n = 10); L = 1.075-1.386 mm; a = 14-14.1; b = 5.9-6; c = 17-21: V = 50 -61 %. Males (n - 10); L = 1.089-1.168 mm; a = 11.8-16.5; b = 6-6.7; c = 17.4-18.8.

Head w i t h 6 l i p s s l i g h t l y o f f s e t , more so i n the female than i n 174

the male: each bears 2 spiny p a p i l l a e . Stoma long and wide: me-tarhabdions each w i t h 3 r i d g e - l i k e t e e t h : t e l o r h a b d i o n s from the s l i g h t l y widened stoma base ( F i g . 2B). Esophagus ( F i g . 2A) c o n s i s t i n g of precorpus, median c y l i n d r i c a l b u l b , isthmus and t e r m i n a l v a l v a t e d c o l l a r b u l b . Esophagus c o l l a r envelops about 35-40 % of the stoma.

F i g . 3 : Pelodera t e r e s (Schneider, 1866) , Dougherty, 1955 A - Nematode stoma. B - Female f r o n t end w i t h esophagus,late­r a l view. C - Female v u l v a r e g i o n w i t h eggs, l a t e r a l view. D -Female t a i l , l a t e r a l view. E - Male t a i l , v e n t r a l view. F - Fe­male egg.

Vulva about h a l f body l e n g t h , thus about 50 t o 6 l % of female body l e n g t h . Female t a i l 63-66 /a l o n g , dome shaped. Anal open­in g very near t a i l end ( F i g . 20 and D).

Male t a i l peloderan and w i t h a closed bursa. Bursa supported by 10 p a i r s of caudal p a p i l l a e ( F i g . 2E, F, G). Spicules 46-58 xx, p a i r e d , fused and knobbed a n t e r i o r l y , gubernaculum about h a l f l e n g t h of s p i c u l e s ( F i g . 2H). H a b i t a t : O n i t i c e l l u s ( E u o n i t i c e l l u s ) p a l l e n s O l i v . L o c a l i t y : Abu-Rawash, Cairo, UAR.

2-2. Pelodera (Pelodera) t e r e s (Schneider, 1866) Dougherty, 1955 ( F i g . 3 )

Females (n = 10): L - 1.052-1.584 mm; a = 8.2-12; b = 5-7 - 6 . 9 ; c = 37 .6-43.0; V = 56.3-62 .5 % .

Males (n = 10): L = 1 . 1 5-1 . 4 3 mmj a = 19 - 2 3 ; b = 7 . 5 - 7 . 7 ; c = 19-20.

C u t i c l e w i t h f i n e transverse s t r i a e . L i p s rounded, c o n i c a l , formine: an open cup: each w i t h three p a p i l l a e . Stoma 28-30/1 long by 7 ix wide: c h e i l o r h a b d i o n s inconspicuous, each metarhab-dion bearing three e q u a l l y long t e e t h ( F i g . 3A). Esophagus swollen t o form two bulbs. Esophageal c o l l a r enveloping l e s s than h a l f of stoma. Herve r i n g surrounding isthmus of esopha­gus. Excretory pore opening l a t e r a l l y behind basal bulb of o e ­sophagus ( F i g . 3 B ) . Female a d u l t w i t h two gonads, ov a r i e s r e -f l e x e d as f a r as v u l v a . Uterus c o n t a i n i n g about 18 eggs, mean size of egg 38x96 yu. Female t a i l 28 -33 xx l o n g , domeshaped, w i t h a f i n e t e r m i n a l process ( F i g . 30, D, P).

Male t a i l 60-70 xx, w i t h a conspicuous bursa supported by 10 p a i r s of caudal p a p i l l a e . Spicules 50 -52 xx, p a i r e d and knobbed a n t e r i o r l y , gubernaculum 22-23 xx ( F i g . 3E). H a b i t a t : O n i t i c e l l u s ( E u o n i t i c e l l u s ) p a l l e n s O l i v . L o c a l i t y : Abu-Rawash, Cairo, UAR. 176

3. O n i t i s a l e x i a Klug (= sphinx Har.)

A number of 46 a d u l t O n i t i s a l e x i s Klug (= sphinx H a r . ) , ( C o l . , Scarabaeidae) were c o l l e c t e d both from heaps of organic matter and wet sandy s o i l s a t Abu-Rawash. Only 18 i n s e c t s ( a t a r a t e of 39.13 %) were found t o be i n f e s t e d w i t h l a r v a l nematodes. The i n s e c t s were c o l l e c t e d at v a r i o u s dates duri n g a p e r i o d be­g i n n i n g i n October, 1966 and ending i n May, 1967.

The nematode lar v a e were not l i v i n g beneath the e l y t r a as usu­a l l y expected, but fe e d i n g on the c e r v i c a l membranes, 35-120 i n d i v i d u a l s per i n s e c t . The nematode l a r v a e i s o l a t e d from the i n f e s t e d b e e t l e s were i n the l a r v a l I I I and p r e a d u l t stages. A f t e r e x t r a c t i o n w i t h a p a r t of the c e r v i c a l t i s s u e s and placed i n drops of d i s t i l l e d water on g l a s s - s l i d e s (25 r e p e t i t i o n s ) ,

P i g . .4 : Heoaplectana b i b i o n i s Bovien, 1937 A - Female a d u l t , l a t e r a l view. B - Female f r o n t end w i t h com­p l e t e esophagus. C - Female v u l v a , l a t e r a l view. D - Female t a i l , l a t e r a l view. E - Male t a i l , l a t e r a l view.

177

they were incubated at 27°C. A f t e r a p e r i o d of 6 days, the l a r ­vae developed i n t o male and female a d u l t s r e p r e s e n t i n g Pelode­ r a s e r r a t a (Körner i n Osche, 1952) Dougherty, 1955, Pelodera t e r e s (Schneider, 1866) Dougherty, 1955, and Neoaplectana b i b i - onis Bovien, 1937. Por r e a r i n g , a r t i f i c i a l media as potatoe-scrappings or n u t r i e n t agar were used; the l a t t e r was more s u i ­t a b l e f o r development: 18 b e e t l e s were i n f e s t e d : s i x specimens by Neoapectana b i b i o n i s , 4 by Pelodera s e r r a t a and 8 by Pelode­ra t e r e s . 425 nematode la r v a e were e x t r a c t e d from the 18 i n f e s ­ted b e e t l e s .

The nematode species Pelodera s e r r a t a and Pelodera t e r e s were described above, w h i l e the d e s c r i p t i o n of Neoaplectana b i b i o n i s i s as f o l l o w s :

3-1. Neoaplectana b i b i o n i s Bovien, 1937 ( f i g . 4)

Females (n= 1 0 ) : L = 1.344-3.174 mm; a = 12-14-4; b = 6.9-13-7; c - 32-58.8j V = 60.4-70.6 %. Males (n = 10): L = 0.600-1.250 mm; a = 12 .5-14.4; b = 3-3-5-6; c = 16.2-31.3.

The nematode species i s c h a r a c t e r i z e d by s i x l a b i a l p a p i l l a e surrounding the o r a l opening. Amphids present. Esophagus rhab-d i t o i d , c o n s i s t i n g of median b u l b , isthmus, and t e r m i n a l bulb. Nerve r i n g obvious and e x c r e t o r y pore i n f r o n t of nerve r i n g . One r e c t a l c e l l c l e a r beside end bulb of esophagus ( F i g . 4B).

Adult female sausage-shaped, w i t h s l i g h t l y t a p e r i n g p o s t e r i o r end and b l u n t l y c o n i c a l t a i l . U t e r u s voluminous. Ovaries p a i r e d , s t r o n g l y r e f l e x e d . Female t a i l 24-54 y U , s h o r t and t a p e r i n g .

Male t a i l b l u n t l y rounded or obtuse. Sometimes a small t i p pre­sent. T e s t i s s t r o n g l y r e f l e x e d . Spicules 53-54 u., y e l l o w i s h or brownish, l a r g e and acute w i t h the p r o x i m a l . p o r t i o n headed. Gu­bernaculum about 42-44 / 1 . Numerous caudal p a p i l l a e , a s i n g l e 178

p r e - a n a l , and 11 p a i r s of l a t e r a l p a p i l l a e p r e s e n t . Bursa ab­sent ( F i g . 4B). H a b i t a t : O n i t i s a l e x i s Klug (= sphinx Har.) L o c a l i t y : Abu-Rawash, Cairo, UAR.

F i g . 5 : Caenorhabditis d o l i c h u r a (Schneider, 1866) Dougherty, 1955 '

A - Male t a i l , v e n t r a l view. B - Male t a i l , s p i c u l e s and guber­naculum, l a t e r a l view. D - Female f r o n t end and esophagus . C, E - Male t a i l , l a t e r a l view. F - Female mouth c a v i t y . G -Male t a i l , v e n t r o - l a t e r a l view. H, I - Female t a i l , l a t e r a l view. J - Female v u l v a , l a t e r a l view.

4. Ocnera h i s p i d a Forsk.

Examinations of 136 a d u l t b e e t l e s of Ocnera h i s p i d a Forsk. (Co­l e o p t e r a : Tenebrionidae) showed t h a t only 22 specimens were i n ­f e s t e d w i t h nematodes (16.17 % ) . Beetles were c o l l e c t e d at Ker-dasa (a v i l l a g e about 10 km from Cairo) and at Mosttord farm (near Cairo) on v a r i o u s dates d u r i n g a p e r i o d extending from September, 1966 t o November, 1967.

A number of 215 p a r a s i t e s were e x t r a c t e d from the 22 i n f e s t e d b e e t l e s (an average of 9.8 nematodes per b e e t l e ) .

Nematodes were found crowded underneath the e l y t r a . I n t e r n a l examination showed no i n f e s t a t i o n w i t h nematodes. E x t e r n a l i n ­f e s t a t i o n occured i n both male and female b e e t l e s .

I s o l a t i o n and r e a r i n g experiments on several a r t i f i c i a l media proved t h a t the meat e x t r a c t medium was the most s u i t a b l e f o r nematode growth.

Microscopic examination and measurements of both nematode male and female a d u l t s proved t h a t the represented nematode species i s Caenorhabditis d o l i c h u r a (Schneider, 1866) Dougherty, 1955.

The f o l l o w i n g i s the morphological d e s c r i p t i o n o f the nematode.

4-1. Caenorhabditis d o l i c h u r a (Schneider, 1866) Dougherty, 1955 ( P i g . 5 )

Females (n = 10): L = 0.924-0.980 mm; a = 15 . 6-22; b = 5-7-6.0; c = 12.3-13-, V = 50.8-71 %. Males (n - 10): L = 0 .924-0 .957 mmj a = 20 - 2 4 . 3 ; b = 6.04-6.2; c = 20-24.2.

The nematode species i s c h a r a c t e r i z e d by a head w i t h s i x o f f s e t l i p s , e a c h l i p w i t h a f i n e p a p i l l a e . Stoma ( F i g s . 5D and F) about f i v e times as long as wide, metarhabdions each w i t h a p a i r of la r g e apparently h o l l o w t e e t h . Esophageal c o l l a r surrounding about h a l f stoma. Esophagus wi t h o u t a median b u l b . 180

Adult female w i t h a si n g l e gonad, p r o d e l p h i c ( P i g . 5H), uterus w i t h few eggs at a time .Female t a i l " about 71-80 yu l o n g , conoid.

Male t a i l peloderan w i t h nine p a i r s of caudal p a p i l l a e : three p a i r s preanal, t h r e e p a i r s postanal and three p a i r s i n the t a i l end ( F i g s . 5 A,B,C,E and G). Bursa p r e s e n t . Spicules separate, s t r a i g h t , p r o x i m a l l y knobbed and reaching 32-46 ja i n l e n g t h : gubernaculum more than h a l f l e n g t h of s p i c u l e s . H a b i t a t : Ocnera h i s p i d a Forsk. L o c a l i t y : Kerdasa and Mosttord, Cairo, UAR.

5. Pentodon algerinum Herbst (= dispar Baud syn. )

Specimens of Pentodon algerinum Herbst. (= dispar Baud syn.) (Coleoptera: Scarabaeidae) were c o l l e c t e d from v a r i o u s manure heaps at Abu-Rawash. Of 106 b e e t l e s , examined i n t e r n a l l y and e x t e r n a l l y , only 41 specimens (38.68 % ) , were found t o be i n ­f e s t e d w i t h e x t e r n a l nematodes. The p a r a s i t e s were crowded only underneath the e l y t r a .

779 nematode l a r v a e were i s o l a t e d from the i n f e s t e d i n d i v i ­d u als. They were reared on a r t i f i c i a l c u l t u r e s , a t t a i n i n g the a d u l t stage. Microscopic examination, measurements and i d e n t i ­f i e r «ion proved t h a t they represented three nematode species: Mononchoides s t r i a t u s (Bütschli, 1876) Goodey, 1963, Neoaplec­ tana b i b i o n i s Bovien, 1937, and Pelodera s e r r a t a (Körner i n Osche, 1 9 5 2 ) Dougherty, 1955« The two former species were found mixed under the e l y t r a of 19 i n f e s t e d b e e t l e s , w h i l e the t h i r d species was found s i n g l y under the e l y t r a of the remaining 22 i n f e s t e d b e e t l e s .

A r t i f i c i a l c u l t u r e s (potatoe-scrappings and n u t r i e n t - a g a r ) were used f o r r e a r i n g the nematode l a r v a e . The former medium was l e s s s u i t a b l e than the l a t t e r f o r development, as v e r i f i e d by d a i l y examination.

The two l a t t e r nematode species were described b e f o r e , the de­s c r i p t i o n of the t h i r d species i s as f o l l o w s : T O -

5 - 1 . Mononchoides s t r i a t u s (Bütachli, 1876) Goodey, I963 ( M g . 6 )

Females (n = 10): L = 1.023-1.238 mm; a = 20.4-21.4; b = 7 . 7 -9.2; c = 2 .9 -3 .1 ; V = 41.8-45.2 %. Maies (n = 1 0 ) : L = 0.89-1.18 mm; a = 20.02-24.2; b = 6 .9-8.45 c = 2.5-3.2.

The nematode species can be de f i n e d by the . f o l l o w i n g characte­r i s t i c s : L i p r i n g d i v i d e d i n t o 12 i n d i v i d u a l r i b s , each b i f i d at i t s a n t e r i o r end .Each r i b s l o p i n g outwards p o s t e r i o r l y , l i k e an i n v e r t e d f u n n e l . Telorhabdions w e l l developed and forming a d e f i n i t e tube before lumen of esophagus ( F i g s . 6 A,B). Esopha­gus compact, w i t h v a l v a t e d t e r m i n a l bulb ( F i g . 6c).

Female w i t h two w e l l developed gonads, d i d e l p h i c , o v a r i e s r e -f l e x e d and vulva n e a r l y median. Female t a i l l o n g a n d f i l i f o r m .

Male t a i l ( F i g s . 6 F,G) wi t h o u t bursa and w i t h 10 p a i r s of cau­dal p a p i l l a e : three p a i r s p r e a n a l , others arranged at t a i l end. I t i s f i l i f o r m and 356-370 /u l o n g . Spicules 34-36 /a, p a i r e d , slender and prox i m a t e l y knobbed. Gubernaculum n e a r l y h a l f s p i ­cules l e n g t h w i t h a proximal cap and d i s t a l groove. H a b i t a t : Pentodon algerinum (= d i s p a r ) L o c a l i t y : Abu-Rawash, Cairo, UAR.

6 . Saprinus semipunctatus F.

Beetles of Saprinus semipunctatus F. (Coleoptera: H i s t e r i d a e ) were c o l l e c t e d a t d i f f e r e n t places i n c u l t i v a t e d sandy s o i l s at Abu-Rawash. E x t e r n a l and i n t e r n a l examination showed t h a t i n f e s t a t i o n w i t h nematode l a r v a e occurred only beneath the e l y t r a . Of 110 beetles only 41 i n d i v i d u a l s were i n f e s t e d (37.3 % ) . Nematode i n f e s t a t i o n ranged from 5 to 72 nematode l a r v a e per i n s e c t . The e x t r a c t e d larvae were reared on a r t i f i ­c i a l media, a f t e r one week the larvae developed i n t o male and female a d u l t s . 182

Microscopic examination and measurements of both sexes showed t h a t the nematodes represented two species: Pelodera s e r r a t a and Pelodera t e r e s .

1210 nematode worms were e x t r a c t e d from 41 i n f e s t e d b e e t l e s : 18 b e e t l e s were harbouring 450 nematode l a r v a e of Pelodera s e r r a -t a , and 23 b e e t l e s 760 l a r v a e o f Pelodera t e r e s

The two nematode species were p r e v i o u s l y described ( P i g s . 3, 4 ) .

P i g . 6 : Mononchoides s t r i a t u s (Bütschli, 1876) Goodey, 1963 A - Female stoma, l a t e r a l view. B - Female stoma, v e n t r a l view. C - Female f r o n t end w i t h esophagus. D - Female t a i l , l a t e r a l view. E - Male t a i l , l a t e r a l view. F - Male t a i l , v e n t r a l view. G - Gubernaculum of male.

Table 1 In s e c t s i n f e s t e d w i t h nematodes

Species of i n s e c t s examined

Number of i n s e c t s examined

Number of i n f e s t e d i n s e c t s

% of i n s e c t i n f e s t a t i o n Nematode species

Order: COLEOPTERA 1 Anisodactylus v i r e n s

Dej - 197 25 7.6 Panagrolaimus subelonga­

t u s Nematoda sp ?

2 O n i t i c e l l u s p a l l e n s O l i v . 202 121 59.9

Pelodera s e r r a t a Pelodera t e r e s

3 O n i t i s a l e x i s Klug 46 18 38.1 Neoaplectana b i b i o n i s Pelodera s e r r a t a Pelodera t e r e s

4 Ocnera h i s p i d a Porsk. 136 22 16.2 Caenorhabditis d o l i c h u r a

5 Pentodon algerinum Herbst 106 41 36.7

Mononchoides s t r i a t u s Neoaplectana b i b i o n i s Pelodera s e r r a t a

6 Saprinus semipuncta­tus P. 110 41 37.3

Pelodera s e r r a t a Pelodera t e r e s

T o t a l 797 286

Discussion

Although nematodes i n c l u d e dangerous pests causing damages t o both animals and p l a n t s , c e r t a i n species can be used b e n e f i ­c i a l l y i n b i o l o g i c a l c o n t r o l . Nematodes associated w i t h i n s e c t s are of great importance as b i o l o g i c a l agents against i n s e c t s , t h e r e f o r e the r e l a t i o n s h i p s between nematodes and i n s e c t s are of i n t e r e s t and t o be s t u d i e d .

Nematodes have been found attached e x t e r n a l l y to i n s e c t s on t h e i r abdominal segments, l e g s , g e n i t a l segments, beneath the e l y t r a and on the s o f t t i s s u e s between head and t h o r a x . Nema­tode l a r v a e l o c a t e d on s o f t t i s s u e s feed on them and cause some harm t o the i n s e c t : i f the nematode l a r v a e appear i n great num­bers, they i n h i b i t host a c t i v i t y and i n some cases lead t o i t s death. While these nematodes are harmful t o t h e i r h o s t s , those e x i s t i n g beneath the e l y t r a , on the legs and abdominal segments ;

are n o t . Such i n s e c t s serve as c a r r i e r s f o r nematodes and con­t r i b u t e t o t h e i r d i s t r i b u t i o n among another animal and p l a n t hosts .

I n the present study a number of 797 b e e t l e s were c o l l e c t e d and examined both e x t e r n a l l y and i n t e r n a l l y as t o t h e i r i n f e s t a t i o n w i t h nematodes. 268 specimens of the 797 b e e t l e s (33 .6 % ) were found t o be i n f e s t e d w i t h nematodes, a l l e x t e r n a l l y (Table 6 ) . 6341 nematode l a r v a e were e x t r a c t e d from 268 i n f e s t e d i n s e c t s and reared on c e r t a i n a r t i f i c i a l media where a d u l t stages were reached. Nematodes found represented seven species assignable t o f o u r families.The f a m i l y Rhabditidae i s represented by three species, Neoaplectanidae by o n l y one, D i p l o g a s t e r i d a e by two, and Panagrolaimidae by one species. Rate of i n f e s t a t i o n ranged from 7 .61 % i n Anisodactylus v i r e n s Dej. t o 59.9 % i n O n i t i c e l ­l u s p a l l e n s O l i v .

L i a b i l i t y t o i n f e s t a t i o n by c e r t a i n nematode species v a r i e d among the i n s e c t species examined. While O n i t i s a l e x i s Klug and Pentodon algerinum Herbst were l i a b l e t o be i n f e s t e d by three

nematode species,other i n s e c t species were invaded e i t h e r by two or one nematode species o n l y . Nematode i n f e s t a t i o n was ob­vious and i n t e n s i v e d u r i n g the warm months and i n i n s e c t s which i n h a b i t the s o i l , farmyard manure, decaying or r o t t i n g organic m a t e r i a l - s i t e s where contamination w i t h nematode hosts i s mo­re f r e q u e n t .

ALI , VI. WAHAB, A. - E L - K I F E L , A. H . : Egyiptomi bogarak fonálférgei. I I .

A szerzők a Carabidae, Scarabaeidae, Tenebrionidae és H i s t e r i -dae családba tartozó 797 bogár külső és belső vizsgálatát vé­gezték e l p a r a z i t i k u s nematodák kimutatása céljából. A talált lárvákból mesterséges táptalajon kitenyésztett aduitusokon vé­gezték e l a f a j o k meghatározását. A bogarak közül 268 (33,6 %) v o l t nematodákkál fertőzött. Kizárólag külső élősködőket talál­t a k , amelyek 4 család 7 fajához tartozónak b i z o n y u l t a k .

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Received: 12. 11. 1971 Dr. AL I , M. Department of Economic Entomology,

A g r i c u l t u r a l College, Al-Azhar U n i v e r s i t y , Cairo

Arab Republic of Egypt

Present address: Növényvédelmi Kutató Intézet,

3860 Keszthely, Felszabadulás u. l / a , Hungary