Hover Fly, Heliophilus fasciatus
Hover fly larvae, like most fly larvae are maggots and relatively sedentary. Female hover flies lay eggs on plants with aphids, the primary food of predatory hover fly larvae. If aphid populations are adequate, development and survival to the pupa stage can approach 100%.
Ants can alter the math. The reason is clear from a study involving ants, syrphid larvae and aphids.* In the presence of ants, only about half the hover flies survive to the pupa stage. Female hover flies are less likely to lay eggs on aphid infested plants when ants are present, an adaptation to reduced survival of offspring. Ants can have substantial effects on biological control of insect pests.
*Alireza Amiri-Jami, Hussein Sadeghi-Namaghi & Francis Gilbert. Performance of a predatory hoverfly feeding on Myzus persicae reared on two brassicaceous plants varies with ant attendance. Biological Control 105 (2017) 49–55.
Illustrations of Visual System Nerves: a) Mammal b) Cephalopod c) House Fly
Illustrator: Ramon y Cahal
Ramon y Cahal is considered the “Father of Neuroscience”. He was passionate about the inner workings of the brain and sought to better understand the human condition by understanding the brain. Ramon y Cahal was a superb histologist and illustrator who became the sixth person awarded the Nobel Prize for Physiology and Medicine in 1906. He created images of nerve cells and their connections that are still used in neuroscience textbooks today, over 100 years later.
Ramon y Cahal compared nervous systems of different animals and documented profound differences in their organization. He illustrated the nerves in visual systems of a mammal, a cephalopod and a house fly (see image). The house fly visual system is an order of magnitude smaller than the cephalopod but just as complex if not moreso. However, processing information has enough similarities that studies in insects can be applied to parts of the human visual system.
New instrumentation and molecular tools have greatly increased our ability to map nervous systems with finer detail and better measurements of their activity. In the nervous system, function is reflected in the structure a key concept proposed by Ramon y Cahal over a century ago. His pioneering work on neuroanatomy still guides us today.
Apple maggots are pests of apples in the Eastern United States where active control measures are necessary. Apple maggots overwinter as pupae, lay eggs on apples in summer and pupate in the soil in fall. The apple maggot can develop on a several plant species including horticultural plants. The apple maggot is a North American species that became a pest of apples when it moved from hawthorne to apple in the 1860s. Apples are not native to North America, but other plants in the family Rosaceae such as hawthorne are native.
In apple production areas of the western US such as Washington [state], the apple maggot has not been a pest. Apple maggot arrived on the west coast in 1979 (possibly by someone moving infested fruit) where it has established. Quarantines are in place to prevent movement of apple maggot into the apple growing regions of eastern Washington.
Of particular concern is the handling of “Municipal Green Waste”. Urban areas on the west coast need to dispose of plant waste: leaves, brush, twigs, limbs and old fruit. Composting green waste is a cost effective measure to recycle nutrients. Demand for composting has out paced local composting capacity. This led a company to build a composting facility for Seattle compost east of the Cascades in an area where apple maggot is not found. Discoveries of apple maggot at the compost facility resulted in closure of the facility. A risk analysis concluded that the threat to the apple industry was real and made recommendations as to how municipal green waste might be treated to exclude apple maggots.
This is one more example of how integrated our ecosystems are. Practices that are good for urban areas may adversely affect agricultural areas and agricultural practices can adversely affect urban areas. It is important to have a view of the whole ecosystem rather than exclusively focus on a narrow component in order to prevent bad outcomes.
Zika Virus is becoming old news that drops from public consciousness. However, Zika is still in the US and is still being locally transmitted in Florida despite spraying and efforts at eradication. Florida has the second highest number of reported Zika cases among the states at 836 as of January 17, 2017. Only New York has more cases: 1001. The majority of infections occur in travelers to other countries where Zika is epidemic. However, local transmission of Zika has occurred in 2 states, Florida (211 cases) and Texas (6 cases), with new locally transmitted cases reported for Florida in December 2016. Local transmission so far only occurs where Aedes aegypti is present. New York has more reported cases than Florida but no local transmission has been reported to date.
The numbers of Zika related birth defects continues to rise. In US states, 37 babies (another 5 have died) have birth defects linked to the Zika virus, including brain damage and deformities deafness, microcephaly, eye problems and nerve and joint conditions. The total is expected to rise. In retrospective studies, 6 Hawaiian babies with microcephaly born after 2009 have mothers that were exposed to Zika, possibly when traveling to Pacific Islands. Zika may have been causing birth defects in the US for over half a decade before the 2016 outbreak focused world attention on the problem. Zika does not always cause birth defects. 940 pregnant women infected with Zika have given birth to babies with no noted birth defects so far. This is good news. We don’t know with certainty why birth defects occur in some cases but not others.
In the US, the Territory of Puerto Rico has by far the most cases with over 34,000 and counting. 51 cases of the neurological disorder, Guillain-Barré syndrome, have been reported in US territories. The emerging pattern in the US suggests that most Zika transmission will be confined to southern states with Aedes aegypti, travelers to infected areas and their partners. When visiting infected areas, a good repellent is a reasonable precaution.
The State of Indiana has announced a new conservation program called CORRIDORS (Conservation On Rivers and Roadways Intended to Develop Opportunities for Resources and Species). The Indiana Department of Natural Resources has 3 partner agencies, Indiana Department of Transportation (INDOT), USDA Natural Resources Conservation Service (NRCS) & Pheasants Forever and Quail Forever. The IN DNR will provide techinical advice and some payments for landowners who sign onto the habitat enhancement and conservation program. INDOT is restructuring its right of way management. They will remove invasive species, establish or encourage native plants and reduce mowing and spraying to preserve habitat and wildlife. The NCRS will provide technical assistance for efforts to improve water quality and wildlife habitat. Pheasants Forever and Quail Forever has Farm Bill money from the Federal Government to improve habitat quality.
For INDOT mowing and spraying is expensive and energy intensive. Maintenance expenses can be reduced by more selective mowing [both areas mowed and timing of mowing]. This will hopefully free funds for other parts of the conservation effort. Although some citizens will complain about the reduced mowing, the program can be a win-win for taxpayers and conservationists. Although narrow, right of ways occupy substantial areas of land that are not otherwise developed. If managed with conservation in mind, these right of ways can be habitat for many insects including bee pollinators and Monarch Butterflies. Changes in mowing practices is one recommendation for providing more food plants and habitat for Monarchs.
Image Chung and Moon*
Millipedes, like insects have a single pair of antennae on the head. The antennae can be tucked away when the millipede is curled in a defensive position or extended to the front and sides to receive sensory information when the millipede is in motion. The antennae of the millipede support several types of sensory hairs that respond to chemicals or mechanical deformation. They can detect chemicals on surfaces and airborne odors. Mechanoreceptors respond to wind and air currents and to tactile stimuli when the antennae contact surfaces.
Compared to insects such as crickets that use their antennae for navigation by touch in the dark of night, the antennae of millipedes are much shorter in relation to body length. Thus, they are better adapted for sense of smell than use as “feelers”. It is not clear what odors are important to their survival. Millipedes do not exhibit a strong response to most odors. What do millipedes smell and how do they react? That can only be known by further study.
*Kyung‐Hwun Chung & Myung‐Jin Moon. Antennal sensory organs in the female millipede Orthomorphella pekuensis. Integrative Biosciences 10:183-189.
Tarsal Pads On the Male-Millipede Orthomorphella pekuensis
Image Chung and Moon*
Some millipede species will practice a form of mate guarding. The male remains with the female, riding on her back until her eggs have been laid. To avoid dislodgment, male millipedes must cling to the smooth surface of the female. Chung and Moon prepared scanning electron micrograph images of male and female millipedes. Their image (left, arrow) reveals dense bristles extending from the ventral side of the male millipede tarsus forming an adhesive pad. The tarsal pads are present on the male, that must cling, but not on the female that has no need to cling.
*Kyung-Hwun CHUNG and Myung-Jin MOON. Microstructure of the adhesive pad in the millipede Orthomorphella pekuensis. Entomological Research 38 (2008) 216–220