Chromosome complement of two species of Amelinae (Dictyoptera: Mantodea)

Summary The karyotypes ofApteromantis aptera (Fuente) andAmeles decolor (Charpentier) are described. Chromosomes numbers in females are 2n=30 and 2n=28 respectively. Sex determination mechanism in both is XO-XX.     

The chromosome complement ofNasalis larvatus (Wurm 1781)

Riassunto I cromosomi diNasalis larvatus presentano un numero diploide di 2n=48. Il cariotipo presenta moite similitudini con quello delle altreColobinae e con leHylobatinae.

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Supported in part by a grant from the Italian Consiglio Nazionale delle Ricerche No. 7854/H.     

Variation in chromosome number in the sheep headflyHydrotaea irritans (Fallen) (Diptera: Muscidae)

Summary Variation in the number of chromosomes was found in sheep headflies, ranging from 12 to 15 chromosomes. Of these, five pairs were common among all individuals. Among 9 larvae no males were identified.     

Maturation of the female Tetrix undulata (Swrb) (Orthoptera, Tetrigidae): influence of the male and copulation:parthenogenetic egg-laying]

The percentage of laying females and laying time, are compared between mature females (diapause break by chilling) and diapause strain females (diapause not broken by chilling) reared with mature male or diapause male or without male. For the same physiological state of the females (mature or diapause) there is no difference in the percentage of females laying, when they are reared with mature male or with diapause one or none; but the laying time is shortest with mature male, longer with male in diapause, even longer without male. Parthenogenetic egg-pods can be obtain. Rearing with mature males does not break the reproductive diapause of females. In parthenogenetic egg-pods the number of eggs is short for low diapause females; greater for mature ones and greatest for females with strong diapause broken by a corpus allatum implant of mature female of Locusta migratoria. Corpus allatum of the low diapause strain of females of Tetrix undulata have less activity than that of mature females. Few parthenogenetic eggs develop, even less hatch. In Tetrix undulata parthenogenesis is accidental.     

Free amino acids in the testes ofGryllotalpa africana beauvois (Orthoptera,Gryllidae)

Zusammenfassung Zweidimensionale Chromatographie der Hoden vonG. africana ergibt das Vorkommen von elf Aminosäuren: Leucin (Isoleucin), Valin, Prolin, Tyrosin, Alanin, Glycin, Serin, Glutaminsäure und Asparaginsäure. Höchste Konzentration fand sich bei Prolin und Asparaginsäure, niedrigste bei Serin und Tyrosin.     

Polyploidization and production of abnormal spermatids inPsophus stridulus (Orthoptera)

Summary Abnormal spermatids exhibiting variation in the number of adjunct centrioles (ACs) (from two to eight) have been analyzed in a spontaneous mutant grasshopper characterized by a high tendency to form polyploid meiocytes. Results show that the observed polyploidization of these cells increases the number of abnormal gametes and, although diploid spermatids (with two ACs) are the most frequent, higher levels of ploidy are also produced. The variation in the number of ACs, the level of ploidy in the sperm and the presence of polyploid meiocytes, are topics briefly discussed.     

Differential staining of a heterochromatic zone inArcyptera fusca (Orthoptera)

Summary A homogeneous heterochromatic zone obtained with the direct application of the C-banding technique is unravelled into 2 sub-zones with the successive application of orcein staining and the C-banding method in the grasshopperArcyptera fusca.This work was supported by a grant awarded to Professor A. Sañudo to whom we are very grateful.     

Screening of newly synthesized non-alkylating sterilant compounds against the adultChrotogonus trachypterus Blanch. (Orthoptera: Acrididae)

Summary Out of the 9 new non-alkylating compounds screened againstC. trachypterus, the compounds 62206, 24220 and 51160 have been found most effective, 51007 and 50882 exhibit intermediate effectiveness, 61914 only slightly effective and 50994, 2406 and 51240 almost non-effective.This work was financed out of PL 480 USA funds.     

Effects of reserpine on development of Oedipoda coerulescens L. (Acrididae, Orthoptera) (author's transl)

Inhibitory effects of reserpine on ecdysis and chromatic adaptation in Oedipoda appear to be linked with changes observed in both neural and neuro-endocrine regulating systems.     

Toxicity of some insecticides for crowded and isolated nymphs ofGryllodes sigillatus Wlk. (Orthoptera: Gryllidae)

Summary 6 insecticides; chlordane, malathion, fenitrothion, pyrethrum, rotenone and sevin, were screened againstGryllodes sigillatus Wlk. reared under crowded and isolated conditions. Chlordane was found to be most toxic, followed by malation, fenitrothion, pyrethrum, rotenone and sevin. Insects reared under crowded conditions were more susceptible to insecticides than insects reared under isolated conditions.Acknowledgments. The authors are grateful to Dr S. C. Saxena for providing all facilities.     

W chromosome in the Indian water snake (checkered keel back)Natrix piscator (colubridae)

Zusammenfassung Die diploide Chromosomenzahl beider Geschlechter beträgt 40: 10 Macrochromosomen und 30 Microchromosomen. Die GeschlechtschromosomenZZ () undZW () sind cytologisch erkennbar.     

Supernumerary (B) chromosome inAnopheles indefinitus (Diptera,Culicidae)

Summary Larval brain mitotic karyotype ofAn. indefinitus from Kanchanaburi exhibits a supernumerary (B) chromosome which is apparently common in that population. 1 or 2 B-chromosomes have been observed in the samples from 5 isofemale lines examined.Acknowledgments. We thank K. Mongkolpanya and P. Kittayarak for species identification. Part of this work was supported by Mahidol University Research Fund and AFRIMS.