Trichomes: the first line of defense against herbivores (Trichoplusia ni).

Pest insects have significant economic, environmental and social impacts on society. The cabbage looper, Trichoplusia ni, is a pest native to the United States. They feed on many vegetable plants including all members of the Brassicaceae family, and even tomatoes. When herbivores initiate feeding on a host plant, they present "cues”, which the plant perceives and uses to help rapidly mobilize its defenses in response to the herbivore’s attack on the plant. This study was designed to determine if T. ni, is able to induce the production of leaf hairs or trichomes on the newly forming leaves of tomato plants. In some plant species, herbivores or defoliation triggers the production of increased trichomes which act as a defense mechanism against herbivores. We will be answering three questions: The first being, "Does cabbage looper saliva induce trichomes?”. To investigate this question, we will ablate the spinneret so that the insect is unable to salivate on the plant. Our next question addresses, “Does increased trichome density interfere with growth of cabbage loopers?". A bioassay procedure will be used to determine whether the feeding and growth rates of T. ni were affected by the various trichome densities (specifically glandular) on the host plant. The third question addresses if “Cabbage looper saliva can affect the expression of the defense gene, proteinase inhibitor 2 ?”. These experiments were conducted to better understand the interaction between insects and plants to facilitate the development of new pest control systems.