Humans have co-existed with leeches for so long, according to Siddall, that just about every language has a word for leech. 3. theyâve made a comeback in medicine.
The lettuce aphid is a problem worldwide and has recently become problematic in the western United States and Canada (Liu and McCreight 2006; McCreight 2008). However, the first three species of aphids listed above are most economically damaging in Florida (Nuessly and Webb 2010). Although heavy aphid pressure can stunt plants, the major problem aphids cause is head contamination, which makes lettuce unmarketable.
The life history of many aphids is complex and unusual. Enormous populations of aphids can be built up in a short period of time. Although considerable variation occurs between species, a typical life history is described as follows.Aphids generally overwinter as fertilized eggs.hey feed on both coniferous and deciduous plants. Effective control of aphids has been a problem to homeowners and landscape managers for years. Some of the more common aphids include the green peach aphid, melon aphid, tuliptree aphid, giant bark aphid, white pine aphid, and rose aphid.