本會台灣昆蟲期刊第44期最新文章，由Dr. Seiji Tanaka 田中誠二博士發表，以下資訊感謝Dr. Seiji Tanaka提供：
Newly hatched larvae face various physical and biological threats. To counter these, insects have evolved mechanisms to control hatching timing, ensuring larvae emerge at the 'right' time and often hatch synchronously. In some insects, embryo-to-embryo communication may facilitate synchronous hatching within an egg mass. Eggs in these species are typically in contact, allowing vibrational signals to transmit between them.
The dock leaf beetle, Gastrophysa atrocyanea, lays its eggs in masses on the underside of dock plant leaves such as Rumex japonicus and Rumex obtusifolius. The eggs form a single layer, adhering to each other and the leaf surface via a sticky substance. The egg stage is brief, lasting about six days at 20 °C, resulting in nearly simultaneous hatching within each mass.
This study examined the mechanisms underlying hatching synchrony and its relationship to cannibalism in G. atrocyanea. Experiments investigated the effects of egg group size on hatching time and intervals under laboratory conditions. Additionally, the influence of hatching time differences on egg and larval survival was tested with varying food availability. Oophagy rates at different larval stages, in the presence and absence of food, were also evaluated.
The results revealed that eggs kept singly hatched earlier than those in groups of four. However, hatching intervals within groups of four were consistent, whether eggs were kept singly, in pairs, or in groups. This suggests that interactions affecting hatching synchrony, such as those seen in grasshoppers through embryo-to-embryo communication, are absent in G. atrocyanea. Conversely, the hatching interval from the first to the last egg increased with larger group sizes. Survival rates within 12 hours of hatching did not differ significantly between singly kept eggs and those in masses.
Early-hatched larvae rarely engaged in oophagy when eggs laid on the same day or one day apart were placed together on small leaf discs. Significant egg mortality occurred only when eggs laid two or more days apart were combined, though this effect diminished on larger leaves. These findings indicate that cannibalism within the same egg mass is not a driving factor in the evolution of hatching synchrony in G. atrocyanea.
文章來源 : 田中誠二。2024。蓼藍齒脛金花蟲 (Gastrophysa atrocyanea，鞘翅目：金花蟲科) 的孵化同步性與同類相食。台灣昆蟲。44 1 :98-112. DOI:10.6662/TESFE.202404_44(2).004
文章連結：https://reurl.cc/042xyA