Studies on some specific biological and temporal factors affecting mating and/or oviposition in Tribolium castaneum (Hbst.) coleoptera: Tenebrionidae

Abstract

RESUMOM achos a fêm eas de Tribolium castan eu m , recém -eclcdidos, parearam para copulação durante os dois períodos de 8 h oras (octetos) (de 6:00 a té 14:00 ou de 14:00 a té 22:00 hs) de um ciclo diário de 24 horas e com eçaram a oviposição no l.o ou 2.o d ia após o p aream ento. O casal m onogâm ico, geralm en te p erfaz m ú ltip las copulações (n a m aioria das vezes, 3 ou 4) durante aqueles perío dos. O coito é sem pre curto e dura de 25 a 208 segundos. D iferen ças em idade de m ach os e fêm eas n a época da copulação produzem variações in teressa n tes nos padrões de oviposição n este inseto. Ém todas as situ a çõ es exp erim en tais estudadas, n ão foi a feta d a a viabilidade de 100% dos ovos p ostos p elas fêm eas. ABSTRACT F reshly em erged m ales and fem ales of Tribolium castan eu m coupled for m a tin g during any of tw o 8-hour periods (octets) (6.00 th ro u g h 14.00 or 14.00 through 22.00) of a 24-hour daily cycle com m ence ovip osition on th e 1st or 2nd day follow in g pairing. The two sexes co n stitu tin g a sin gle pair gen erally perform m ultip le m atin gs (in m ost in sta n ces 3 or 4 tim es) during any of th ese octets. C oitus session s betw een m ales and fem ales are alw ays brief and range from 25 to 208 seconds. D ifferen ces in age of m ales and fem a les a t th e tim e of th eir m atin g produce in terestin g variation s in th e ovip osition al p a ttern s in th is in sec t w ith o u t a ffe c tin g th e 100% viab ility of eggs la id by th e fem a les in all ex p erim en tal situ a tio n s studied.

A behavioural assessment of the impact of some environmental and physiological factors on the reproductive potential ofCorcyra cephalonica (Stainton) (Lepidoptera: Pyralidae)

“…Nevertheless, within a prescribed quartet on any single day they performed only one coition. The existence of this multiple mating phenomenon in the reproductive behaviour of the rice moth, while contradicting the observations of Chakravorty and Das (1983a), was, to some extent, similar to that already reported for this species by Sehgal and Chand (1978) and to that observed in certain other stored products insects like Tribolium confusum (Good 1933), Tribolium destructor (Reynolds 1944), Trogoderma qranarium (Karnavar 1972) and Tribotium castaneum (Singh and Krishna 1980).But the fact that the duration ofa single mating act in C. cephalonica was short, though not as brief as that recorded in T. castaneum (Singh and Krishna 1980),testifies the inherent incapability of these insects to remain in coition for extended periods, notwithstanding provision of facility for these moths to accomplish such a task associated with their reproductive activity. Evidently, these findings raise interesting questions concerning the not yet elucidated extrinsic and intrinsic conditions regulating frequency and duration of mating in this insect.…”

“…The reason for choosing the nocturnal part of the daily time-cycle to hold these insects in "couples" is because of the observed pronounced high sexual activity of both sexes leading to mating, like in a number of other lepidopteran members (Engelmann 1970), during the night hours. For the remaining part of the normal day-night rhythm, when the sexes were not paired, they were, however, allowed to enjoy the company of each other only through a metallic wire-mesh partition installed in a manner basically identical to that reported for Earias [abia (Shahi and Krishna 1979)or for Triboltum castaneum (Singh and Krishna 1980). In addition to procurement of egg output and egg viability data, continuous observation was made to record the number of matings and the length of each copulatory act per female during a quartet of every experimental day when the insects were in the paired state.…”

Nitrogen budget ofCallosobruchus maculatus larva developing in different host seed species

“…The pattern of food utilization and energy allocation to reproduction in insects is significantly influenced by humidity (Pingale 1976), food quality (Singh and Krishna 1980), temperature (White and Sinha 1981), life style (Cairns 1982) and interaction of one or more of these factors (Muthukrishnan and Pandian 1984). Scriber and Slansky (1981) showed that nitrogen and water content of food may significantly influence the assimilation efficiency of lepidopteran insects.…”