In the face of global climate change, the understanding of how aphid‐symbiont relationships are affected by heat shock is critical. We evaluated the effects of heat shock on the pea aphid, Acyrthosiphon pisum Harris (Hemiptera: Aphididae), and its obligate endosymbiont Buchnera aphidicola Munson et al. by means of quantitative PCR in treated aphids and their offspring. First‐instar aphids received a single heat shock (35 °C for 6 h), repetitive heat shocks (repeat of the single heat shock for 3 days), or a control treatment (constant 20 °C). We evaluated the impacts on aphid body length and Buchnera and aphid gene densities, estimated from the number of copies of bacterial 16S‐rRNA and nuclear elongation factor 1‐alpha (EF1α) genes, respectively. Heat shock negatively affected aphid body length and Buchnera and EF1α gene densities. Heat‐shocked aphids contained lower densities of Buchnera and EF1α genes than control aphids when body length was kept constant. When Buchnera and EF1α gene densities were represented on a log–log scale, Buchnera densities increased with EF1α densities in all treatments, but Buchnera densities showed negative allometry with EF1α densities. Compared to control aphids, heat‐shocked aphids contained lower Buchnera densities relative to EF1α densities. Some heat‐shocked aphids became sterile if their Buchnera gene density was lower than a threshold (ca. 42 000 copies). The offspring of aphids subjected to a single heat shock recovered the number of Buchnera, but the offspring of aphids subjected to repetitive heat shocks exhibited markedly lower Buchnera and EF1α densities. Thus, heat shock negatively affects both aphid and Buchnera cell proliferation, in the heat shock‐treated generation as well as in their offspring, but the impact is more severe on Buchnera. Because the symbiont supplies essential amino acids, vitamins, and an essential protein, this could reduce aphid development and reproduction and possibly leads to extinction of local populations.

Abstract:The pattern of butterfly abundance, their diversity with abiotic (temperature, humidity, rainfall, photoperiod) and biotic (plants) factors were studied in the Butterfly Research Park (BRP) at Bhawal National Park, Gazipur,

Developmental stages in the life cycle of lycaenid butterfly, Lampides boeticus (Lepidoptera : Lycaenidae) and their association with the host plant (Lupinus nanus) (Fabaceae) were examined both in the laboratory under 29 ± 3ºC temperature with RH 78 ± 2% and field conditions. The oviposition behaviour, incubation and larval‐pupal period of the butterfly and its association with L. nanus were studied. The host plant association and duration of developmental stages were given importance. Duration of life cycle (egg to adult) was 19 ‐ 21 days. Eggs, four larval instars and pupal stages were distinct. Lampides boeticus was found deeply associated with L. nanus to complete its life cycle. This association with host plant was characterized and evidenced by the use of host leaves, flowers, buds and seeds ( pods) both in the larval (11 ‐ 13 days) and pupal (4 ‐ 6 days) stages. The incubation period, different larval instars and pupal stage were found to be associated deeply with the phenological phases of the host plant. Dhaka Univ. J. Biol. Sci. 24(1): 43-52, 2015 (January)

Developmental stages of pierid butterfly Catopsilia crocale Fabricius (Lepidoptera: Pieridae) and its association with Cassia alata: Family-Leguminosae (host plant) was studied in the laboratory under 24 ± 5C temperature with RH 66 ± 2%. The host plant association and duration of developmental stages was given importance. Duration of life cycle (egg to adult) was 22.0 ± 0.8 days. The incubation period, larval and pupal period were 6.65 ± 0.4, 10.1 ± 0.8 and 6.5 ± 0.44 days, respectively. Eggs, five larval instars and pupal stages were distinct. Correlation was found among the development of larval instars, amount of food consumption and excretion of faeces. The association of C. crocale with host plant was characterized and evidenced by the use of C. alata leaves, buds, stems and shoots for egg laying and for complete development of the larval (9 -11 days) and pupal (6 -7 days) stages. The incubation period, different larval instars and pupal stage were found to be deeply associated with the phenological phases of the host plant.