San Bruno Elfin
Photo: Larry Orsak
Species on the Endangered Species List are protected from harm by human activities intentional or unintentional. When companies operate in areas that contain endangered species, the companies must develop a plan that will minimize the harm or potential harm to those species.
Plans are submitted to the Fish and Wildlife Service, the federal department that manages endangered species. The FWS will review the plans by its own staff and scientists, send them out for review by other scientists and make them available for review by the public. The philosophy: Many eyes are more likely to uncover problems.
The FWS has a comment period for individuals or organizations to submit thoughts and recommendations. One function of the US regulatory process is to give everyone a chance to be heard. It is certain that organized conservation groups will make use of this opportunity.
Sensitive insects in the affected area include:
Delta green ground beetle (Elaphrus viridis)
Bay checkerspot butterfly (Euphydryas editha bayensis)
Callippe silverspot butterfly (Speyeria callippe callippe)
Lange’s metalmark butterfly (Apodemia mormo langei
Mission blue butterfly (Plebejus icarioides missionensis)
San Bruno elfin butterfly (Incisalia mossii bayensis),
Photo: Ole Bidstrup
The parasitic wasp, Chelonus inanitus, relies on viruses to successfully colonize its hosts. When the wasp injects eggs into its host, the eggs are accompanied by viruses. The viruses selectively colonize the cells of the host immune system and destroy them. This allows the developing wasp to avoid attack by immune cells. The viruses also arrest the development of the caterpillar host.
The Chelonus inanitus ichnovirus is fully integrated into the wasp life cycle. The virus only replicates in the nucleus of the calyx cells in the female reproductive system. Both double stranded virus DNA and protein capsule are produced and assembled in the nucleus of the calyx cells. The virus particles are released from the cells by budding, in which the viruses are surrounded by the outer cell membrane which is pinched off, releasing the virus in to the oviduct of the wasp.
The viruses evolved from ancestors that lived independently, but are now integrated into the wasp such that neither the wasp nor the virus would survive without the other.
U. Albrecht, T. Wyler, R. Pfister-Wilhelm, A. Gruber, P. Stettler, P. Heiniger, E. Kurt, D. Schiimperli and B. Lanzrein. Polydnavirus of the parasitic wasp Chelonus inanitus (Braconidae): characterization, genome organization and time point of replication. Journal of General Virology (1994) 75: 3353-3363.
Photo: Bob Self
Formosan termites have infested the Gulf Coast of the US since the late 1940s when they hitched a ride on solid wooden packing used to crate returning military equipment. Formosan termites are a threat to wooden structure in New Orleans historic French Quarter and have spread east to Florida. Formosan termites are now having a significant effect on Jacksonville, having done enough damage to the historic Women’s Club building to lead to its condemnation and destruction.
Jacksonville is now engaging in a program to limit the damage. Formosan termites can nest in landscape trees, weakening and destroying them as well as damage buildings. This creates a large number of nesting sites that make location of nests difficult. Termite management depends on identifying areas with significant termite populations. In spring, termite reproductives swarm to find mates and start new colonies. It is easier to locate termite locations by trapping flying adults.
Jacksonville is deploying 50 termite traps that use the termites attraction to light. Solar powered lights are paired with a sticky trap that will capture termites and other insects attracted to lights. The data from the traps will be used to help inspectors search for nests, locate and destroy them to limit the population.
Once an invasive species like the Formosan termite establishes in an area, elimination or eradication may be impossible. The only option to reduce damage may be an expensive management program.
Cornitermes cumulans nest
Photo: Marcella Cosarinsky*
Cornitermes cumulus is a neotropical termite that builds mounds more than a meter high. An average of over 300 mounds per hectare are found in pastures, cultivated lands and Savannas in Brazil and Paraguay. How are tiny insects able to construct such a large structure?
Like all large projects, they start small and then grow. A nest is originally founded by a mated female and her male partner. Together they excavate an underground chamber (copularium) where they rear the first brood. This brood becomes workers that will build a large structure.
The workers create walls from soil and saliva that extend just above the soil surface creating a flat mound. A hive or “habitacle” where the brood is raised is attached to the walls in the center of the mound. As the colony grows the habitacle must be expanded, but is confined by the walls. The workers add to the wall on the outside and remove material from the insides of the wall to create more interior space. Workers build galleries between the outer wall and the habitacle that help support and protect the colony. Wall building and removal occurs at the top of the mound as well as on the sides. The habitacle exapands upward as well as outward so it is located in the center of the mound but its height is relocated above the soil surface.
The termites are able to change the consistency of the walls they create. When the mound is small, the walls are made of fine grain particles. As the mound becomes large, the walls are made from coarser particles. This change can affect the ventilation of the mound. Although they may appear as a “simple mound of soil” on the outside, the mounds are remarkably complex structures.
*Marcela I. Cosarinsky. The Nest Growth of the Neotropical Mound-Building Termite, Cornitermes cumulans: A Micromorphological Analysis. Journal of Insect Science 11(122):122 · September 2011
Arboreal Termite Nest
Photo: Leponce & colleagues*
New Guinea contains many interesting species of tropical insects including arboreal species of termites. Rather than building nests on the ground, these termites build nests on the trunks and limbs of trees. These termites can be found infesting coconut plantations.
There are 3 primary species of arboreal termites, Nasutitermes princeps, Nasutitermes novarumhebridarum and Microcerotermes biroi. Nasutitermes novarumhebridarum has small colonies in dead or dying trees and does not compete with the other species found in healthy trees.
Nasutitermes princeps is both a larger termite and has larger colonies than Microcerotermes biroi. Nasutitermes princeps will travel beyond its foraging territory, attack and displace colonies of Microcerotermes biroi. This behavior leaves zones of coconut trees unoccupied by any of the arboreal termite species. However, exclusion may not persist long. Microcerotermes biroi reproduces by swarms of winged reproductives. The many termite pairs can start many colonies. They rapidly reinvade areas that are not patrolled by Nasutitermes princeps.
*Maurice Leponce, Yves Roisin and Jacques M. Pasteels. Structure and Dynamics of the Arboreal Termite Community in New Guinean Coconut Plantations. BOTROPICA 29(2): 193-203 1997
Monarch Butterflies have left their overwintering site in Mexico and are now reaching Texas. The good news is the warm and rainy weather in Texas this year has produced large numbers of flowering plants that are sources of nectar and abundant milkweeds already sprouting. Texas is considered especially important to Monarchs as the first available habitat on their journey north. The bad news is that warmer than usual temperatures in Mexico raises the metabolism of the overwintering butterflies and more rapidly depletes their reserves.
Despite their low overwintering numbers, Monarch populations can rapidly expand given the right environmental conditions. Abundant food, milkweeds for the caterpillars and nectar for the adults are part of those conditions. The declines in Monarch population this century are correlated with reduction in milkweed plants in agricultural fields. Milkweed reduction does not eliminate other factors in Monarch decline. Further study may identify other important factors such as climate or other environmental changes. Hopefully conditions will be good this year for a population rebound.
Head of Eastern Subterranean Termite
The Eastern Subterranean Termite, Reticulotermes flavipes, is one of the most destructive termite pests in the US. This termite builds multiple interconnected galleries in wood. When nesting in a wooden structure, multiple interconnected galleries require substantially more chewing of the wood to create tunnels and hollow out space for new galleries. If the termite colony made a single gallery, the termites would be easier to locate and damage to be repaired restricted in location. However, Reticulitermes flavipes makes multiple galleries, sometimes abandoning the original location to another remote site.
Why do these termites build multiple galleries? There are multiple hypotheses, but no definitive answer. It may be a strategy to escape pathogens that can contaminate a nest area. It may be to locate to a better food source or closer to water. In nature, feeding by these termites is primarily on dead trees and logs. Creation of multiple interconnected galleries allows numerous smaller pieces of wood to be colonized and through interconnections the colony can grow to a size unlimited by available food.